Clutch for lifting-jacks



(No Model.) 2 Sheets-Sheet 1. A. A. STROM.

CLUTCH FOB. LIFTING JAGKS.

No.` 347,279. Patented Aug'. 10, 1886.

IL PUERS, PhmLimughpmr. wnhngtan. D. c,

2 Sheets- Sheet 2.

(No Model.)

A.. A. sTRoM. CLUTCH FOR LIPTING, JAGKS.'

Patented Aug. 10-

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@i MMM N. PETERS Pham-Lithngnphnr. wnhirggton. llc

4 5o front elevation of a lifting-jack provided with UNITED STATES PATENTv @Finca AUSTIN, ILLINOIS.

CLUTCH FOR LlFTlNG-JACKS.

SPECIFICATION forming part of Letters Patent No. 347,279, dated August 10, 1886.

Original application filed November 3, 1R85, Serial No. 181,731. Divided and this application filed December i7. 1885. Serial No- To all whom it may concern:

Be it known that I, AXEL A. STRoM, a citi` zen of the United States, residing at Austin, in the county of Cook and State of Illinois, have 5 invented certainnew and useful Improvements j in Friction Clutches; and I hereby declare the following to be a full, clear, and exact description ofthe same. 4

Friction-clutches ofthe general class to which to myinvention belongs are employed in various mechanical devices, though the particular connection with which I design to use the clutch portion of my invention is a lifting-bar, such as is used in lifting-jacks, as shown in the present drawings, andn shown and described in my application, Serial No. 181,731, filed November 3, 1885, of which the present is a divisional application, and upon which Letters Patent' of the United States No. 2o 344,794. were granted me on the 29th day of June, 1886.

My invention consists in the general .con- `struction ofvmyimproved device, which comprises, broadly, recessed clutch-blocks, one above the other, upon alifting -bar which passes through them, and having each recess beveled andcontaining a roller normally in contact with the lifting-bar, one clutch-block heilig stationary to constitute the retaining- 3o clutch and the other movable to constitute the liftingclutch.

My invention also consists in means for ref leasing the bar from Contact with each roller,

and it further consistsin certain details of construction and combinations 'of parts, all as hereinafter more fully set forth.

' The term each recess employed in the foregoing recital of invention and in the appended claims is notintended to intimate that 4o there must, necessarily be more than one recess in each clutch-block, though only one is sufficient for all ordinary purposes; but it is intended to be generic in the sense that itwill include the use of one or more recesses, each of which contains a roller5and the word stationary with reference to the retaining-clutch is not intended to signify absolute rigidity of position, as will hereinafter appear.

Referring to the drawings, Figure l is a my improvement; Fig. 2, a vertical central section of the same, presenting a side elevation;

(No model.)

Fig. 3, a side elevation of the same with a portion of the-operating-lever broken away; Fig.

4, a broken sectional view, in side elevation, of 5 5 a lifting-jack provided with my improvement, wherein each clutch has single recess, roller, and releasing device; Fig. 5, a broken sectional view showing details of construction of Inyimprovement in its modified form ,wherein two each of the-recesses, rollers, and releasing devices are provided in each clutch, and Fig. 6, a sectional plan view taken on the line 6 6 of Fig. 4. i

A is the lifting-bar,within a hollow standard, A', cast, preferably in the form shown, with a vertical slot, r, in its front side to permit the vertical movement of the foot A2 of the lifting-bar.

B is a clutch-block surrounding the bar A, and having the recess or 'chamber C formed in its opening, through which the lifting-bar extends, and slanting toward the latter from its upper side where itis closed, as shown, ending in a vertical recess, q.

D is a loose roller within the recess or chamber C and extending transversely across the lifting-bar. f

From this much of the description the principle of the operation will be readily understood,for -it will be seen that the clutch can easily be moved downward upon the bar A, a suitable lever, F, being used for actuating it, and connected for the purpose at opposite sides ofthe clutch-block B, and fnlcrumed in a shifting bearing, as shown at x in Fig. 3, all as fully described in my aforesaid Letters Patent; but that any attempt to move it upward causes the roller to wedge itself between the beveled wall in the recessed clutch-block and the bar, and thus produce a binding which increases with the force exerted. By actuating the clutch, therefore, upon the lifting-bar A upward, movement of the clutch will lift the bar and raise a weight thatv may be imposed upon it.

To permit thelifting-clntch B to be lowered for a fresh grip upon the bar without permitting the latter and its superimposed weight to fall, another friction-clutch, B', in construction exactly like the clutch Bor differing from the latter in aslight mechanical detail,as shown and hereinafter described, is employed as a retainingclutch, which must be anchored or in IOO some way secured to be rendered practically stationary, which is shown in the drawings to be accomplished, as one way, by making the retaining clutch part of the standard A. Vhen, therefore, the lifting-clutch B is lowered for a fresh grip, the bar is firmly held from falling by the impingement against it of the roller D in the rctainingclutch B', preferably below the other, though the reverse position ofthe two clutches might be used if desired, the retaining-clutch ot` course being stationary, as described, and the lifting-clutch movable. The release of the bar to permit it to fall from a raised position is accomplished by a hinged stop, E, on the cover ofthe retainingeluteh, which hinge, when raised for the purpose, enters t-he vertical recess l] with the downward movement of the lifting-clutcluand by its contact with the roller D thereof stops or releases the latter, and thus overcomes itswedging effect. The normal position, however, ofthe stop l or releasing mechanism is down in the position shown by the dotted lilies. out of coincidence with the vertical recess q.

As two clutches have to be used with the lifting-clutch preferably uppermost, the most convenient position for the releasing hinged stop E is upon the cover ot' the lower or retaining clutch, the roller D of which may, on the release of the roller l) in the lifting-clutch, as described, be released by hand by mea-ns of a lever, E, fulerumed, as shown, and having its short arm within the recess of the retaining clutch-block, into which it enters through a vertical. opening, q. The clutches may, if desired, cach be provided with two, preferably covered, beveled recesses, C, on opposite sides of the bar, cach containing a wcdgingroller, I), as clearly shown in Fig. 5, when the releasing` device E must be provided in dupli cate, and the lever E is bifurcated, as shown, to cause each of its short arms to enter a recess, C, inthe retaining-clutch below the roller contained therein.

\Vhat I claim as new, and desire to secure by Letters Patent, is-

l. rlhe combination, with a liftingbar, ofa movable recessed clutel1blocl ,]3, and a stationary recessed clutch-block, B', one above the other, upon the lifting-barto be clutched, which passes through them, and having each recess beveled and containing a roller, and a lever for actuating the lifting clutch-block` substantially as described.

2. rlhe combination, with a lifting bar, of a movable recessed clutch-block, B, and a stationary recessed clutch-block, B, one above the other, upon the lifting-bar to be clutched, l

which passes through them, and having each recess beveled and containing a roller, and means, substantially as described, for releasing the retaining-elutcl1 B at will, whereby the lifting-bar may be raised intcrmittingly by operating the lifting clutch-block l through the medium of a suitable lever, and caused to descend by releasing the gripping-roller in the retaining-clutch, substantially as set forth.

3. rlhe combination, with a lifting-bar, of a movable recessed clutch-block, l5, and a statiouary recessed clutch-block, l', one above the other, on the lifting-bar to be clutched, which passes through them, and having each recess beveled and containing a roller, means, substantially as described, for releasing at. will each roller in the retaining clutch-block, and a stop for arresting at will each roller iu the lifting clutch-block, whereby the bar may be raised iutermittingly by operating the lifting clutch-block through the medium of a suitable lever,and caused to drop directly to its lowest position by lowering the lifting clutch-block and releasing each gripping-roller of theretaining clutch-block, substantially as set forth.

1. rlhe combination, with a lifting-bar, of a movable recessed clutclrblocli, B, and a stationary recessed clutch-block, l, one above the other, on the lifting-bar to be clutched, which passes through them, and having each recess beveled and containing a roller, and a lever, E, for releasing each roller in theretaining clutch-block l at will, whereby the lifting-bar may be raised interinitti ugly by operating the lifting clutch-block through the medium of a suitable lever, and caused to descend by releasing each gripping-roller in the retaining-clutch, substantially as described.

5. The combination, with a lifting-bar, of a movable recessed cliitclrbloclt, 13, and a stationary recessed clutch-block, ll', one above the other, on the lifting-bar to be clutched, which passes through theln, and having each recess beveled and containing a roller, a lever, E, for releasing at will each rollei.I in the re taining clutch-block, and stops lf), for arrest ing at will each roller in the lifting clutchblock, whereby the bar maybe raised intermittingly by operating the lifting elutclrhloek through the medium of a suitable lever, and caused to drop directly to its lowest position by lowering the lifting clutclrblocl; and releasing each gripping-roller of the retaining clutch-block, substantially as described.

AXEL A. STROM.

IOO

IOS 

